ROS: Basic Concepts, Sources, Cellular Signaling, and its Implications in Aging Pathways

Figure 3

Cysteine oxidation is the site mainly described for redox signaling. Proteins sensitive to oxidation at thiols (cysteine amino acids contain thiols groups exposed for reaction) groups are a target for peroxide hydrogen and other oxidants. (a) First oxidation can change the conformation of the protein, which in turn will send a signal derived from this oxidation. Then, antioxidants can return the protein to its native form. However, in conditions such as oxidative stress, excessive oxidation can occur, driving proteins to irreversible inactivation, a process found in many age-related diseases. (b) Diverse oxidant can lead to a broad range of cysteine modifications that imply different signals relevant to cellular environment.

(a)

(b)